Electric vehicle
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| 14.4 Hybrid Vehicles Hybrid vehicles which cannot be recharged from the mains but run entirely on petrol have become well established. Two examples are the Honda Insight and the Toyota Prius, which have really made an impact on the world of car design, and brought electric cars that people can easily use onto the market. They are discussed below. These, and a steadily increasing number of alternatives from almost all the major motor manufacturers, can be purchased now at very reasonable prices. Table 14.6 The Nissan Leaf Body style Five-door hatchback Layout Front engine, front wheel drive Electric motor kW (110 hp) permanent magnet synchronous motor Transmission Single-speed direct drive Battery 24 kWh lithium ion battery Range 117 km (73 miles) (EPA km (109 miles) (NEDC) 76–169 km (47–105 miles) (Nissan) Wheelbase 2700 mm (106.3 in) Length 4445 mm (175.0 in) Width 1770 mm (69.7 in) Height 1550 mm (61.0 in) Curb weight kg (3354 lb) 280 Electric Vehicle Technology Explained, Second Edition Table 14.7 The Mitsubishi MiEV Body style Five-door hatchback Electric motor kW (63 hp) permanent magnet synchronous motor mounted on rear axle, 180 N m torque Transmission Single-speed reduction gear Battery 16 kWh (lithium ion battery) Range 160 km (99 miles) (Japanese cycle km (62 miles) (US EPA cycle) Top speed mph (130 kph) Wheelbase 2550 mm (100.4 in) Length 3395 mm (133.7 in mm (144.9 in) (US) Width 1475 mm (58.1 in mm (62.4 in) (US) (excluding side mirrors) Height 1600 mm (63.0 in mm (63.6 in) (US) Curb weight kg (2400 lb) 14.4.1 The Honda Insight The Honda Insight is a hybrid vehicle combining a conventional petrol-driven engine with an additional motor driven by a battery. The engine and motor can both be used to propel the vehicle. The Insight employs a system Honda calls the Integrated Motor Assist (IMA) system. The Insight does not get recharged from the mains in the same way as a conventional EV. Instead its benefits derive from using the IC engine in conjunction with the battery and motor/generator system to maximise energy efficiency and to minimise fuel consumption. When there is surplus power available from the engine it is used to recharge the batteries from the motor/generator. The motor/generator is also used to slow the vehicle and thus recover the kinetic energy into the battery. When the brake pedal is pressed lightly, the Insight’s electric motor operates in regeneration mode, and the car begins to slow just as it would with normal brakes. Once the brake pedal is pressed further, the normal brakes come into play, slowing the car down even more. In heavy traffic the car is driven from the batteries via the motor/generator only. Hence it can be classified as a partial zero-emission vehicle (PZEV). It is a parallel hybrid, as outlined in Figure 2.3. The electric motor/generator has a maximum power of 10 kW, and is about 6 cm thick, between the engine and the gearbox, and directly connected to the crankshaft. The body chassis is designed for low weight while at the same time meeting crash test requirements. All structural components and most body panels are extruded or die- cast aluminium, while front fenders and rear fender skirts area recyclable ABS/nylon composite. The car’s independent front suspension uses lightweight, forged-aluminium suspension arms and aluminium front suspension knuckles. The braking system’s front callipers are also aluminium alloy, as are the rear brake drums. The rear suspension is a highly compact twist-beam design that sits completely below the Insight’s flat cargo floor, along with the lightweight plastic-resin 40 l (10.6 US gallon) Recent Electric Vehicles 281 fuel tank and gas-pressurised rear shock absorbers. The rear suspension is also designed to help absorb the energy of a rear impact. At the heart of the Insight’s IMA system is a compact, 1 l, three-cylinder petrol IC engine. The engine uses lean-burn technology, low-friction design features and lightweight materials such as aluminium, magnesium and special plastics, in combination with anew lean-burn-compatible NOx catalyst, to achieve the levels of efficiency and low emissions in petrol engine technology. The specification for the Insight is given in Table 14.8. 14.4.2 The Toyota Prius At about the same time as the Insight was launched, Toyota also launched its Prius vehicle. This is also a petrol IC engine/electric hybrid. It has less good fuel consumption figures, but has more luggage space and five seats. It has enjoyed considerable sales success, and has really put this type of vehicle into the public eye. This has been helped by the appeal of the car to a number of celebrities. The car is powered by a valve, four-cylinder engine of 1.5 l using variable valve timing. The engine displacement is with a bore of 75 mm and stroke of 84.7 mm. The engine also incorporates an aluminium double overhead cam (DOHC) and multi-point electronic fuel injection. This system allows the engine to maintain a high level of fuel efficiency. Download 3.49 Mb. Share with your friends:
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